User Guide

64 Kaspersky Anti-Spam 3.0
4.5.6. Notifications about rejected
messages
If the Reject this message action has been specified as the action over
messages with a specific status, filtration server will not route such messages to
their original recipients. Instead, it returns to message sender a notification
informing that mail delivery is impossible.
Filtration server uses two types of notifications. The use of messages of a certain
type is determined by the product settings and recognition results.
The first type of notifications is Reject message. Such message is transmitted to
the sender immediately during an SMTP session together with an error code
informing that the message has not been delivered. The example of an SMTP
session below contains a Reject message text:
Server: 220 mail.mycompamy.com ESMTP
Client: HELO spamhost.whatever.com
Server: 250 mail.mycompamy.com
Client: MAIL FROM: <[e-mail]>
Server: 250 Ok
Client: RCPT TO: <[e-mail]>
Server: 250 Ok
Client: DATA
Server: 354 End data with <CR><LF>.<CR><LF>
Client: >>>
Client: >>> Message text ...
Client: >>>
Client: .
Server: 550 The message is rejected by spam filtering
engine.
Client: QUIT
Server: 221 Bye...
Anti-spam engine will only use Reject messages when message delivery to all
of the specified recipients is forbidden according to the scanning results.
If a message is meant for several recipients and the filtration policies allow its
delivery to at least one of them, then the server will respond during SMTP
session that the message has been accepted. Then it will return to the sender a
Bounce message with information about the recipients whom it did not deliver
the message.